Turbine blade locking apparatus



Aug. 27, 1946.

C. H. MORRIS TURBINE BLADE LOCKING APPARATUS I Filed June 8 1944Patented Aug. 27, i946 UNITED STATES PATENT OFF-ICE 2,406,703, TURBINEBLADE LOCKING APPARATUS Cecil H. Morris, Milwaukee, Wis as sig nor toAllis-Chalmers Manufacturing Company, Milwaukee, Wis, a corporation ofDclaware Application June 8, 1944, Serial N 539,315

This invention relates to packing means insertable in e local e areementof a roov or the k p d d e suee r o tainably e1 gaging the root portionsof blades or other members to be mounted in row forming relation on suchsupport and has for its object the provision of an improved packingmeans eliminating the use of a lock-screw or other special device forsecuring h Pa kin le e i Place while atfording all or" the advantagesinherent in the type of packing disclosed and claimed in R. C. Allenscopending application 8. N. 536,464, filed May 20, 1944. which issued onJanuary 22 1946 as Patent Number 2,393,447.

The "construction and application of packing means embodying theinvention will become readily apparent as the disclosure progresses andparticularly points additional features considered of special importanceand of general application although illustrated and described'as appliedto the mounting of turbine blades in a circumferentially extending bladeroot receiving and. retaining groove.

Accordingly, the invention may beconsidered as consisting of the variousdetails of construction, correlations of elements, and arrangements ofparts as is more fully set forth in the appended claims and in thedetailed description, reference being had to the accompanying drawing,in which:

Fig. 1 is a developed plan view of a partial rotor structure embodyingthe invention;

Fig. 2 is a section taken on line IIII of Fig. 1;

Fig 3 is a view similar to Fig. 2 with the pack-. ing pieces removed;

Fig. 4 is a section taken on line IV-IV of Fig. 1 showing only the firsttwo packing pieces in place;

Fig. 5 is a plan view of the assembly shown in Fig.

Flg. 6 is a view similar to Fig. 5 showing the angular-1y displaceablepiece shifted to the right;

Fig. '7 is a view similar to Fig. 4 showing the relative position ofparts when insertion of the filler piece is started;

Fig. 8 is a View similar to Fig. 7 showing the final position of theangularly displaceable piece;

Fig. 9 is a viewsimilar to Fig. 8 showing the relative position of partswith the filler piece in its lowermost position;

Fig. 10 is a plan view of the assembly shown in Fig. 9;

Fig. 11 is a view similar to Fig. 10 showing the filler piece in itsfinal position;

Fig. 12 is aview taken on line XIL-Xll of Fig.

10 Claims. (01. 253-47) 2 ll' sh owing partial insertion of the wedgetool used driving the projecting element to its final position;

Fig. 13 is a side view of the filler piece;

Fig. 14 is right hand edge view of the element Sh n n F s- 3; r

Fig. 15 is an edge view of the angularly displaceable element;

Fig. 16 is a side view of the element shown in e- .5

Fig. 17 is a top view f the element shown in Figx'15;

Fig. 18 is an edge view of the element shown as being driven toward itsfinal position in F g. 12;

19 is a side view of the element shown in Fi 18; and g Fig. 20 a topview of the element shown in Fig-31% I Reie ring to the drawing it isseen that the invention may be applied to a turbine rotor l embodying acircumierentially extending undercut'gr'oove 2 in which are disposed theroot portions S bladeS 4; the root portions being of a shapecomplementary to the cross sectional configuration of the groove and thegroove having a iocal enlargement S permitting the root portions of theblades to be inserted into the groove and t en shifted a ra ly tor-thepo it on shown in Fig: 3 wherupont hey can be moved len thwiseof thegroove in either direction from the enlarged portion thereof until thegroove is sub.- stantially filled with blades as indicated. The rootportion of each blade presents a pair of oppositely facing, radiallyextending plane surfaces 1 which abut the lilge surfaces on adjacentblades whenthefblades are in properly assembled relation see Fig. 1);the thickness of the root portions, that is'the distance between suchplane surfaces; being sufiicient to eliminate the use of spacing piecesbetween the root portions of adjacent blades. However, thecross-sectional configurationof the groove and whether or not spacingpieces areemployed between the root portions of adjacent blades arefeatures of design an may be varied a des red s e the on r ci- .uisitevin this connection is that the groove and the root portions ofthelblades to be inserted therein be pr'ovided'Wit h suitable coactingretaming surfaces. Consequently, a further description in thisconnection is deemed unnecessary for a complete upderstandingof thepresent invention. v j, t

Th spac remai ne siw t e P an P- P956 1 s rfaqesp e eeies Pr thes c roPe tions of the blades adjacent opposite ends of the local enlargement 6is filled with a plurality of packing pieces 01 elements (four beingshown for purposes of illustration) comprising an element 8 (see Figs;18-20 inclusive) having an edge 9 shaped to conform with thecross-sectional configuration of the right side of groove 2 and its D-posite edge II substantially plain except for a recess I2 therein andhaving a plane, radially extending surface i3 complementary to the likesurfaces presented by the root portions of the blades and an oppositelyfacing concave, cylindrical surface I extending in nonparallel wedgeforming relation to its plane surface I3; an element It (see Figs.15-17, inclusive) of'less radial height than element 8 and having edgesIT and I8 similar to the edges 9 and II, respectively, of element 3except that the laterally projecting base portion of edge I1 is also ofless radial height than the corresponding portion of edge 9, a planeradially extending surface I9 complementary to the like surfacespresented by the root portions of the blades, and an oppositely facing,convex cylindrical surface 2I extending in nonparallel, wedge formingrelation to its plane surface I9; and a filler element 22 havingoppositely facing plane parallel side surfaces 23 and edges 24 and 26identical to the edges 9 and II, respectively, of element 8. V

The convex surface of element I6 is complementary to the concave surfaceI4 of element 8 and these two, elements are adapted to be securelywedged between spaced opposed plane radially extending surfaces simplyby positioning the elements between such surfaces in the abuttinglaterally offset relation indicated in Figs. and 11 whereupon thedesired wedging action can be obtained merely by driving element 8towards the right as viewed in said figures. In this connection, thepacking pieces are preferably assembled in the space remaining betweenthe root portions of the blades by first positioning the elements 8 andIt in such space as indicated in Figs. 4 and 5, then shifting element I6laterally of the groove to the position shown in Fig. 6; then insertingfiller element 22 to the extent indicated in Fig. '7 (in this position,elements 3 and I6 are both resting on the bottom of the groove and oneside of the filler element abuts the opposite plane surface 1 of theadjacent blade root and its opposite side diverges relative to theopposed plane surface I9 of element I6), then angularly shifting elementI6 relative to element 8 and relative to filler element 22 until itsplane surface I9 is in parallel abutting engagement with the opposedsurface of the filler element as indicated in Fig. 8 (the angularshifting of element I 6 when loosely abutting element 8 is readilyeffected by an inward movement of element 22), then inserting the fillerelement to the extent indicated in Fig. 9 which retains element I6 inits angularly displaced relation relative to element 8 (the relativeposition of the elements 8, I6 and 22 being also shown in Fig. 10) andthen shifting element 22 to the right to the extent indicated in Fig. 11whereupon all that remains to be done in order to securely wedge theelements in place is to drive the element 8 to the right until its'lefthand edge II and the recess I2 therein alines with the similar recessededges I8 and 24 of elements I6 and 22, respectively; the recesses in theedges I8 and 24 being designated 26 and 21, respectively.

The top portions of the elements project above the peripheral surface ofthe rotor as indicated in Figs. 2, 4, '7, 8, 9 and 11 and the driving ofelement 8 into wedging relation between element I6 and the plane surfaceI on the adjacent blade can be readily accomplished by first drivingagainst the exposed edge II until such edge is spaced from the adjacentside wall of the groove enlargement 6 whereupon a wedge tool 28 can beinserted as indicated in Fig. 12 and driven downward toward the bottomof the groove thereby shifting elementfi to the right until its edge Mis alined with the corresponding edges of the elements It and 22 andwith the corresponding sides of the root portions of the bladesimmediately adjacent the opposite ends of the local enlargement 6. Inthis connection, the root portions of such blades may be provided withrecesses 29 which are similar to and alined with the recesses in thecorresponding edges of the elements 8, I6 and 22 when these elements arepositioned as shown in Fig. 1. All that remains to complete the assemblyis to insert a plane surfaced piece 3I in the enlargement 6 and bendover its upper reduced edge 32 into the groove formed by the alinedrecesses I2, 26, 21, and 29 provided in the corresponding edges of theelements 8, It, 22 and blades 4-, respectively, as clearly indicated inFig. 2.

It should now be obvious that the edges 9, I1 and 23 of elements 8, I6and 22 are interlockingly engaged with the right hand side wall of thegrooves 2 as viewed in Figs. 2, 3 and 12 which prevents a verticalmovement of such elements relative to each other and relative to thegroove, that a movement of the elements toward the sidewall of the localenlargement opposing their edges Ill, I8 and 24 is impossible with pieceSi in place, and that a vertical upward movement of piece 3| isimpossible when its upper reduced edge 32 is disposed in the grooveformed by the recesses in the opposed edges of the elements 8, IE and 22and the blades 4. In addition, it should also be noted that with theelements 8, I6 and 22 positioned as shown in Fig, l, a vertical movementof element It relative to elements 8 and 22 is prevented by the abuttingengagement of the complementary concave-convex cylindrical surfaces I4and 2| irrespective of whether or not the right hand edge ll of elementIt is actually interlockingly engaged with the opposed side wall ofthegroove Z. In this connection, it is preferable although not necessarythat the complementary concave, convex cylindrical surfaces have acommon axis lying in a horizontal plane normal to a vertical planeincluding or parallel to the plane surface of the element which is to bemade cylindrically concave or convex as herein indicated and that theradius of curvature of such surfaces should not be so great as to rendersuch surfaces incapable of functioning as disclosed.

Whether the right hand edge I! of element I6 is actually interlockinglyengaged with the 0pposed sidewall of the groove is dependent upon theangular displacement of element I '5 relative to element 8 necessary inorder to position its plane surface I9 in parallel relation to theopposed similar surface of element 22; such displacement of element I 6being permitted by having the projecting lower portion of its edge I! ofless height than the radial height of the undercut portion of the grooveas is best indicated in Fig. 12. Obviously, the angular displacement ofelement It relative to element 8 varies the angle between its planesurface I9 and the plane surface I presented by the root portion of theopposed blade; the variation in such angle being sufficient tocompensate for differences in the distance between the plane opposedsurfaces I presented by the root portions of the blades immediately aditcan be angularly displaced relative to element 8 is sufiicient toposition its plane surface 59 in parallel relation to the similaropposed surface I on the root portion of the adjacent blade even thoughthe distance between such surfaces may vary as much or more than 0.2 ofan inch. Consequently, this construction permits the use of standardpacking pieces for grooves of the same size and cross-sectionalconfiguration, that is the elements 8, It and 3| may be made identicaland interchangeably used in such grooves, and since the angle betweenthe surface IQ of element 16 and the opposed surface I of the adjacentblade can be readily made constant by shifting element l6 relative toelement 8, the only correction that has to be made for variations in thedistances between such surfaces isto provide elements 22 of differentthickness.

The driving of element 8 to its final wedging position (compare Figs. 11and 1) circumferentially tightens the root portions of the blades oneither side of the local enlargement to a much greater degree than hasheretofore been possible with known constructions as the lack of spaceprevents driving caulking pieces or the like heneath 'or alongside theroot portions of such blades. Moreover, the packing pieces are securelyretained in wedged relation solely by their own coaction therebyeliminating the necessity of providing a locking screw or other specialdevice for attaining this result. In addition, the disclosedconstruction permits ready assembly of the packing pieces within thespace remaining to be filled by persons with only ordinary skill therebyma terially reducing both the time element and the expense heretoforeconsidered necessary-in order to properly complete the assemblyof such ablade row.

The invention is obviously applicable to theassembly of members otherthan blades in row forming relation on a suitable support and it shouldtherefore be understood that it is not desired to limit the invention tothe exact construction and correlations of features herein shown anddescribed for purposes of illustration as various modifications withinthe scope of the appended claims may occur to persons skilled in theart. v

It is claimed and desired to secure by Letters Patent e 1. Infamounting, for a row of turbine blades or other members including a pairof adjacent members having root portions spaced apart and presentingplane opposed surfaces, a packing means comprising a pair-of elementspositioned between the root portions of said adjacent memhere forinitial relative movement both angularly and linearly with respect to anaxis extending crosswise of said row, said pair of elements havingoppositely facing plane surfaces opposing the plane surfaces presentedby said root portionsand having abutting complementary concave, convexsurfaces extending, in non-parallel relation with respect to saidoppositely facing surfaces and in concentric relation with respect tosaid axis.

2.. In a structure embodying a support having a groove adapted forinterlocking engagement with the root portions of members to be mountedthereon and a plurality of members having root portions interlockinglyengaged with at least one "wall portion of the groove with the root.portions of a pair of adjacent members spaced apart and presenting planeopposed surfaces, a packing means. comprising a pair of elementspresenting oppositely facing plane surfaces and having complementaryconcave, convex cylindrical surface portions extending in nonparallelrelation with respect to said oppositely facing surfaces and inconcentric relation with respect to an axis extending crosswise of saidgroove, said pair of elements being'positioned between the root portionsof said adjacent members for initial relative movement both angularlyand linearly with respect to said axis with said cylindrical surfaceportions effectively abuttingly engaged to permit said relative angularand linear movements of the elements.

3. In a structure embodying a support having a groove adapted forinterlocking engagement: with" the root portions of members to bemounted thereon and a plurality of members having root portionsinterlockingly engaged with at least one wall portion of the groove withthe root portions of a pair of adjacent members spaced apart andpresenting plane opposed surfaces, a packing means comprising a pair ofelements disposed in said groovebetween the planesurfaces presented bythe root portions of said adjacent members for initial relative movementboth crosswise and outwardly with respect to the groove, said pair ofelements having oppositely facing plane surfaces with the plane surfaceof one element abuttingly engaging the plane surface of one root portionand with theplane surface of the other element disposed in opposednonparallel relation with respect to the plane surface of the other rootportion, said pair of elements also having complementary concave, convexsurfaces extending crosswise of said groove in nonparallel relation withrespect to said oppositely facing surfaces and effectively abuttinglyengaged to position the plane surface of said other element in parallelrelation with respect to the plane surface of said other root portion assaid other element is moved outwardly of the groove relative to said oneelement and toincrease the distance between said oppositely facing'planesurfaces as said one element is moved crosswise of the groove relativeto said other element, and means for retaining said other elementpositioned with its plane surface disposed in parallel relation withrespect to the plane surface of said other root portion. as said oneelement is moved crosswise of said groove,

4. In amounting for a row of turbine blades or other members including apair of adjacent members having root portions spaced apart andpresenting plane opposed surfaces, a packing means comprising a pair ofelements having oppositely facing plane surfaces and havingcomplementary concave, convex cylindrical surface portions extending innonparallel relation with respect to said oppositely facing surfaces andin concentric relation with respect to an axis extending transversely ofsaid row, said elements being positioned between the root portions ofsaid adjacent members for relative movement both angularly and linearlywith respect to said axis with one of said oppositely facing surfacesdis posed in parallel relation with respect to the plane surface of oneof said root portions and with said complementary surfaces disposed inabutting engagement,said complementary surfaces being effective as saidelements are moved relatively angularly to position the other one ofsaid opp sitely facing surfaces in parallel relation with respect to theplane surface of the other root portion, and a third element disposed inabutting relation between said other oppositely facing plane surface andsaid other root portion and presenting oppositely facing plane parallelsurfaces'of which one surface engages and retains said other oppositelyfacing plane surface in parallel relation with respect to the planesurface presented by said other root portion, said complementarysurfaces being also effective as said elements are moved relativelylinearly to forcibly urge the root portions of the members lengthwise ofsaid row.

5. In a structure embodying a support provided with a groove having atleast one wall portion thereof adapted for retainably engaging the rootportions of members to be mounted on the support and having a localenlargement permitting the root portions of such members to beretainably inserted in the groove and a plurality of members having rootportions retainably' engaging said one wall portion with the enlargedportion of the groove at least partially free for the insertion ofpacking pieces between plane opposed surfaces presented by the rootportions of a pair of adjacent members, a packing means for the spacebetween said opposed surfaces comprising a pair of elements disposed insaid groove between the root portions of said adjacent members forrelative initial movement both crosswise and outwardly with respect tosaid groove, said pair of elements having oppositely facing planesurfaces opposing the plane surfaces presented by said root portions andhaving complementary concave, convex surfaces extending crosswise ofsaid groove in non-parallel relation with respect to said oppositelyfacing surfaces and effectively abuttingly engaged to produce a wedgingaction lengthwise of said groove in response to a relative crosswisemovement of the elements.

6. In a structure embodying a support provided with a groove having atleast one wall portion thereof adapted for retainably engaging the rootportions of members to be mounted on the support and having a localenlargement permitting the root portions of such members to beretainably inserted in the groove and a plurality of members having rootportions retainably engaging said one wall portion with the enlargedportion of the groove at least partially free for the insertion ofpacking pieces between plane opposed surfaces presented by the rootportions of a pair of adjacent members, a packing means comprising apair of elements presenting oppositely facing plane surfaces and havingcomplementary concave, convex surfaces extending in non-parallelrelation with respect to said oppositely facing surfaces and inconcentric relation with respect to an axis extending crosswise of saidgroove, said elements being positioned between the root portions of saidadjacent members for relative movement both angularly and linearly withrespect to said axis with one of said oppositely facing plane surfacesdisposed in parallel relation with respect to the plane surface of theproximate one of said root portions and with said complementary surfacesdisposed in abutting relation, said complementary surfaces beingeffective as said elements are moved relatively angularly to positionthe other of said oppositely facing surfaces in parallel relation withrespect to the plane surface of said other 'rootportion, a third elementdisposed between and presenting oppositely facing plane parallelsurfaces abutting and retaining the opposed surfaces presented by saidother element and root portion in the parallel relation attained by arelative angular movement of said elements, said complementary surfacesbeing also effective as said elements are moved relatively linearly toforcibly urge the root portions of said members lengthwise of thegroove, said third and pair of elements being of equal width andpresenting exposed plane edge portions forming a substantiallycontinuous plane side surface opposing the side wall of the enlargedportion of said groove, and a plane surfaced fourth piece substantiallyfilling the enlarged portion of said groove and abutting the plane sidesurface presented by the edge portions of said third and pair ofelements.

7. In a structure embodying a support provided with a groove having atleast one wall undercut to retainably receive projections on the rootportions of members to be mounted on the support and having a localenlargement permitting the root portions of such members to beretainably inserted in the groove and a plurality of members having rootportions retainably disposed in said groove with the enlarged portion ofthe groove at least partially free for the insertion of packing piecesbetween plane opposed surfaces presented by the root portions of a pairof adjacent members, a packing means comprising a pair of elementshaving oppositely facing plane surfaces and having abuttingcomplementary concave, convex surfaces extending crosswise of saidgroove in nonparallel relation with respect to said oppositely facingsurfaces, said pair of elements being positioned in said groove betweenthe root portions of said adjacent members for relative linear movementcrosswise of said groove with said complementary surfaces disposed inabutting engagement, said pair of elements also having edge projectionsadapted for interlocking engagement with said undercut wall with theedge projection of one element dimensioned to permit a limited outwardmovement of same relative to the other element to thereby position itsplane surface in parallel relation with respect to the plane surfacepresented by the opposing root portion of the adjacent member.

8. In a structure embodying a support having a groove provided with anundercut side wall and with-a local enlargement permitting insertion ofthe root portions of members to be mountedthereon and a plurality ofmembers having root portions disposed within said groove and.interlockingly engaged with said undercut side wall with the rootportions of a pair of adjacent members spaced apart and presenting planeopposed surfaces disposed adjacent opposite ends of the localenlargement, a packing means comprising a pair of elements positionedbetween the root portions of said adjacent members and presentingoppositely facing plane surfaces opposing the plane surfaces presentedby said root portions, said pair of elements also presenting edgeprojections adapted for interlocking engagement with said undercut sidewall and having complementary concave, convex surfaces extendingcrosswise of said groove in nonparallel relation with respect to saidoppositely facing plane surfaces and abuttingly engaged to permitrelative movement of the elements crosswise of said groove and to rendersuch relative movements effective to forcibly urge said elementslengthwise of the groove and to position said edge projections forinterlocking engagement with said undercut side wall. I

9 9. In a structure embodying a support having a groove provided with anundercut side wall and with a local enlargement permitting insertion ofthe root portions of members to be mounted thereon and a plurality ofmembers having root portions disposed within said groove andinterlockingly engaged with said undercut side wall with the rootportions of a pair of adjacent members spaced apart and presenting planeopposed surfaces disposed adjacent opposite ends of the localenlargement, a packing means comprising a pair of elements positionedbetween the root portions of said adjacent members and presentingoppositely facing plane surfaces opposing the plane surfaces presentedby said root portions, said pair of elements also presenting edgeprojections adapted for interlocking engagement with said undercut sidewall and having complementary concave, convex surfaces extendingcrosswise of said groove in nonparallel relation with respect to saidoppositely facing plane surfaces, one of said lements having its saidedge projection dimensioned to permit said one element to move angularlyrelative to the other ele-.

ment when abutting same with its said edge projection disposed forinterlocking engagement with said undercut side wall.

10. In a mounting for a row of turbine blades or other members includinga pair of adjacent members having root portions spaced apart andpresenting plane opposed surfaces, a packing means comprising a pair ofelements positioned between the root portions of said adjacent membersand having oppositely facing plane surfaces opposing the plane surfacespresented by said root portions, said pair of elements also havingabutting complementary concave, convex surfaces extending crosswise ofsaid row in non-parallel relation with respect to said oppositely facingsurfaces and abuttingly engaged to permit relative cross-wise movementof the elements and to render such movements effective to forcibly urgesaid elements lengthwise of said row without changing the relativeangularity of said oppositely facing plane surfaces. I

CECIL H. MORRIS.

